Question: If $4a + 2b + 9c = 3$ and $6x + 6y = -2$, what is $-8a - 4b - 18c + 12y + 12x$ ?
Answer: $= -8a - 4b - 18c + 12x + 12y$ $= (-2) \cdot (4a + 2b + 9c) + (2) \cdot (6x + 6y)$ $= (-2) \cdot (3) + (2) \cdot (-2)$ $= -6 - 4$ $= -10$